Answer: The tenth term is 76
=======================================================
Explanation:
We use this arithmetic sequence formula to get the nth term

Plug in  and you should get the following:
 and you should get the following:

The tenth term is <u>76</u>
---------
We can verify this by listing out the terms one by one. Start at 4, add on 8 each time, until you generate the 10th term. A table like the one shown below is a good way to keep track of all the terms.

---------
In short, the error is with the "10" in the expression 4+10(8). The student should have used 9 instead. This is because of the n-1 term in  which shifts everything one spot to the left.
 which shifts everything one spot to the left. 
 
        
             
        
        
        
5. The blue one is y >= 5x - 7 
and green is y >= -0.65x + 3
6. y <= (4/5)x
y >= -(5/4)x
 
        
             
        
        
        
First, we know that y is equal to -8x, so we can move the -8x to replace y in the first equation, then in the first equation we get -8x=6x-14, subtract 6x on both sides, -14x=-14, x=1